During the period of this continuation, we propose to extend the study of the relation between syntax and phonetics in human speech processing. The work will focus on how speaker's represent syntactic structures and how such representations are processed in real time prior to and during the execution of speech, combining the disciplines of linguistics, cognitive psychology, and acoustics. This research will be conducted on normal adult and child speakers as well as on the following pathological populations: adult aphasics, right-hemisphere brain damaged adults, autistic children, and mentally retarded children. Experiments on speech production will be conducted to test how speaker's syntactic representations of an utterance constrain the phonetic form of speech timing and fundamental frequency patterns, as measured by computer-aided techniques of acoustic analysis. Studies of aphasic and autistic speech will also include an examination of possible interplay among syntactic, pragmatic, and lexical influences, permitting influences about information-processing stages in speech production. The results of these studies should be applicable to issues involving the diagnosis and treatment of these language-related disorders. In addition, the findings with normal children and adults should provide information about target characteristics of speech timing and fundamental frequency that can be utilized in programs to synthesize speech by rule (an important component of reading machines for the blind) and in improving the prosodic aspects of hearing-impaired children's speech, in conjunction with methods of visual feedback or related training.